Learning WebGL on your iPhone: Radial Blur in GLSL

A misleading title perhaps, since WebGL isn’t generally available to iOS platform developers. Hacks aside, if you’re learning WebGL and have an iPhone it is still a very educational environment. WebGL essentially wraps OpenGL ES in a modern Web browser environment. You can feed data in and out as textures associated with browser canvas areas, […]

Everything Still Looks Like A Graph (but graphs look like maps)

Last October I posted a writeup of some experiments that illustrate item-to-item similarities from Apache Mahout using Gephi for visualization. This was under a heading that quotes Ben Fry, “Everything looks like a graph” (but almost nothing should ever be drawn as one). There was also some followup discussion on the Gephi project blog. I’ve […]

MAMP / MySQL config notes for ‘Repair with keycache’ and table metadata lock

Problem: MySQL taking forever to load some large data dumps. Forever or longer. “mysql> show processlist;” shows it wedged at “Repair with keycache” and “Waiting for table metadata lock”. According to a handy Stack Overflow article, this is a known and dreaded condition, which can be addressed by making sure tmp dir has plenty of […]

Building R’s RGL library for OSX Snow Leopard

RGL is needed for nice interactive 3d plots in R, but a pain to find out how to build on a modern OSX machine. “The rgl package is a visualization device system for R, using OpenGL as the rendering backend. An rgl device at its core is a real-time 3D engine written in C++. It provides […]

Linked Literature, Linked TV – Everything Looks like a Graph

Ben Fry in ‘Visualizing Data‘: Graphs can be a powerful way to represent relationships between data, but they are also a very abstract concept, which means that they run the danger of meaning something only to the creator of the graph. Often, simply showing the structure of the data says very little about what it actually […]

K-means test in Octave

Matlab comes with K-means clustering ‘out of the box’. The GNU Octave work-a-like system doesn’t, and there seem to be quite a few implementations floating around. I picked the first from Google, pretty carelessly, saving as myKmeans.m. These are notes from trying to reproduce this Matlab demo with Octave. Not rocket science but worth writing […]

Video Linking: Archives and Encyclopedias

This is a quick visual teaser for some archive.org-related work I’m doing with NoTube colleagues, and a collaboration with Kingsley Idehen on navigating it. In NoTube we are trying to match people and TV content by using rich linked data representations of both. I love Archive.org and with their help have crawled an experimental subset […]

Easier in RDFa: multiple types and the influence of syntax on semantics

RDF is defined as an abstract data model, plus a collection of practical notations for exchanging RDF descriptions (eg. RDF/XML, RDFa, Turtle/N3). In theory, your data modelling activities are conducted in splendid isolation from the sleazy details of each syntax. RDF vocabularies define classes of thing, and various types of property/relationship that link those things. […]

RDFa in Drupal 7: last call for feedback before alpha release

Stéphane has just posted a call for feedback on the Drupal 7 RDFa design, before the first official alpha release. First reaction above all, is that this is great news! Very happy to see this work maturing. I’ve tried to quickly suggest some tweaks to the vocab, by hacking his diagram in photoshop. All it […]

WOT in RDFa?

(This post is written in RDFa…) To the best of my knowledge, Ludovic Hirlimann‘s PGP fingerprint is 6EFBD26FC7A212B2E093 B9E868F358F6C139647C. You might also be interested in his photos on flickr, or his workplace, Mozilla Messaging. The GPG key details were checked over a Skype video call with me, Ludo and Kaare A. Larsen. This blog post […]

My ’70s Schoolin’ (in RDFa)

I went to Hamsey Green school in the 1970s. Looking in the UK Govt datasets, I see it is listed there with a homepage of ‘http://www.hamsey-green-infant.surrey.sch.uk’ (which doesn’t seem to work). Some queries I’m trying via the SPARQL dataset (I’ll update this post if I make them work…) First a general query, from which I […]

WordPress trust syndication revisited: F2F plugin

This is a followup to my Syndicating trust? Mediawiki, WordPress and OpenID post. I now have a simple implementation that exports data from WordPress: the F2F plugin. Also some experiments with consuming aggregates of this information from multiple sources. FOAF has always had a bias towards describing social things that are shown rather than merely […]

WordPress, TinyMCE and RDFa editors

I’m writing this in WordPress’s ‘Visual’ mode WYSIWYG HTML editor, and thinking “how could it be improved to support RDFa?” Well let’s think. Humm. In RDFa, every section of text is always ‘about’ something, and then has typed links or properties associated with that thing. So there are icons ‘B’ for bold, ‘I’ for italics, […]

Syndicating trust? Mediawiki, WordPress and OpenID

Fancy title but simple code. A periodic update script is setting user/group membership rules on the FOAF wiki based on a list of trusted (for this purpose) OpenIDs exported from a nearby blog. If you’ve commented on the blog using OpenID and it was accepted, this means you can also perform some admin actions (page […]